A range of ion beam techniques have been used to fabricate a variety of photonic guiding structures in the well-known lithium niobate (LiNbO3 or LN) crystals that are of great importance in integrated photonics/optics. This paper reviews the up-to-date research progress of ion-beam-processed LiNbO3 photonic structures and reports on their fabrication, characterization, and applications. Ion beams are being used with this material in a wide range of techniques, as exemplified by the following examples. Ion beam milling/etching can remove the selected surface regions of LiNbO3 crystals via the sputtering effects. Ion implantation and swift ion irradiation can form optical waveguide structures by modifying the surface refractive indices of the LiNbO3 wafers. Crystal ion slicing has been used to obtain bulk-quality LiNbO3 single-crystalline thin films or membranes by exfoliating the implanted layer from the original substrate. Focused ion beams can either generate small structures of micron or submicron dimen...

Photonic guiding structures in lithium niobate crystals produced by energetic ion beams

Modern optical applications need solutions for providing polymer surfaces with antireflective properties. The problems involved in coating comprise thermal limitations, incompatible mechanical properties of coating and substrate materials, and interaction between polymers and plasma. As an alternative for coating, antireflective properties on polymers can also be obtained by hot embossing or by ion etching of surface structures. My objective is to provide the criteria for choosing suitable deposition or structuring methods based on an understanding of plasma-, radiation-, and ion-induced surface phenomena; material compatibility; mechanical and environmental performance; and cost issues. The potential to produce antireflective interference coatings is documented for plasma-enhanced physical- and chemical-vapor-deposition methods, including modern hybrid techniques, as well as for solgel wet-chemical processes. The review about state-of-the-art coatings focuses on the thermoplastic acrylic, polycarbonate, and cycloolefin polymers.

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Review of modern techniques to generate antireflective properties on thermoplastic polymers

Optical property modification of PMMA by ion-beam implantation

Formation of CO2 gas and OH groups in CR-39 plastics due to gamma-ray and ions irradiation

Studies on the nuclear tracks in CR-39 plastics

Optical modifications of polymers by ion beam irradiation

Optical guides are realized by ion irradiation in three polymers: polycarbonate, HIRI, and CR39. Optical properties (index variation, loss) are compared. CR39 waveguides present the best performances (with losses as low as 1 dB/cm); the influence of a curing parameter (initiator concentration), which is directly related to CR39 density and refractive index, is studied.

Refractive-index modifications of some polymeric materials by ion beams

We present a novel route to directly integrate an array of microlenses at the extremity of an optical fiber bundle The method is based on photopolymerization at the end of the fiber The method is based on the control of exposure dose and volume of the deposited droplet of photopolymerizable formulation Optical properties of the integrated microlenses are discussed on the basis of FDTD calculations

Integration of polymer microlens array at fiber bundle extremity by photopolymerization.

Micro-Raman spectroscopy investigation of the electron beam irradiation of LiNbO3 surface for 2D photonic band gap grating inscription

In this work, we report the investigation of 2D photonic crystals in lithium niobate associated with waveguiding structures fabricated by He+ implantation. From the material point of view, the investigation of PBG structures in lithium niobate is of great interest for optoelectronics technology since this crystal is one of the most important materials widely used in integrated and non linear optics. The choice of the implantation technique to produce the waveguide is motivated by the possibility of having both Transverse Electric (TE) and Transverse Magnetic (TM) guided modes in order to obtain a total photonic band gap (PBG).

Claire Darraud

Papers

Optical modifications of polymers by ion beam irradiation

Refractive-index modifications of some polymeric materials by ion beams

Integration of polymer microlens array at fiber bundle extremity by photopolymerization.

Micro-Raman spectroscopy investigation of the electron beam irradiation of LiNbO3 surface for 2D photonic band gap grating inscription

Photonic band gap grating in He+-implanted lithium niobate waveguides